builtin-apply.c

   1 /*
   2  * apply.c
   3  *
   4  * Copyright (C) Linus Torvalds, 2005
   5  *
   6  * This applies patches on top of some (arbitrary) version of the SCM.
   7  *
   8  */
   9 #include <fnmatch.h>
  10 #include "cache.h"
  11 #include "quote.h"
  12 #include "blob.h"
  13 #include "delta.h"
  14 #include "builtin.h"
  15
  16 //  --check turns on checking that the working tree matches the
  17 //    files that are being modified, but doesn't apply the patch
  18 //  --stat does just a diffstat, and doesn't actually apply
  19 //  --numstat does numeric diffstat, and doesn't actually apply
  20 //  --index-info shows the old and new index info for paths if available.
  21 //  --index updates the cache as well.
  22 //  --cached updates only the cache without ever touching the working tree.
  23 //
  24 static const char *prefix;
  25 static int prefix_length = -1;
  26 static int newfd = -1;
  27
  28 static int p_value = 1;
  29 static int allow_binary_replacement = 0;
  30 static int check_index = 0;
  31 static int write_index = 0;
  32 static int cached = 0;
  33 static int diffstat = 0;
  34 static int numstat = 0;
  35 static int summary = 0;
  36 static int check = 0;
  37 static int apply = 1;
  38 static int no_add = 0;
  39 static int show_index_info = 0;
  40 static int line_termination = '\n';
  41 static unsigned long p_context = -1;
  42 static const char apply_usage[] =
  43 "git-apply [--stat] [--numstat] [--summary] [--check] [--index] [--cached] [--apply] [--no-add] [--index-info] [--allow-binary-replacement] [-z] [-pNUM] [-CNUM] [--whitespace=<nowarn|warn|error|error-all|strip>] <patch>...";
  44
  45 static enum whitespace_eol {
  46         nowarn_whitespace,
  47         warn_on_whitespace,
  48         error_on_whitespace,
  49         strip_whitespace,
  50 } new_whitespace = warn_on_whitespace;
  51 static int whitespace_error = 0;
  52 static int squelch_whitespace_errors = 5;
  53 static int applied_after_stripping = 0;
  54 static const char *patch_input_file = NULL;
  55
  56 static void parse_whitespace_option(const char *option)
  57 {
  58         if (!option) {
  59                 new_whitespace = warn_on_whitespace;
  60                 return;
  61         }
  62         if (!strcmp(option, "warn")) {
  63                 new_whitespace = warn_on_whitespace;
  64                 return;
  65         }
  66         if (!strcmp(option, "nowarn")) {
  67                 new_whitespace = nowarn_whitespace;
  68                 return;
  69         }
  70         if (!strcmp(option, "error")) {
  71                 new_whitespace = error_on_whitespace;
  72                 return;
  73         }
  74         if (!strcmp(option, "error-all")) {
  75                 new_whitespace = error_on_whitespace;
  76                 squelch_whitespace_errors = 0;
  77                 return;
  78         }
  79         if (!strcmp(option, "strip")) {
  80                 new_whitespace = strip_whitespace;
  81                 return;
  82         }
  83         die("unrecognized whitespace option '%s'", option);
  84 }
  85
  86 static void set_default_whitespace_mode(const char *whitespace_option)
  87 {
  88         if (!whitespace_option && !apply_default_whitespace) {
  89                 new_whitespace = (apply
  90                                   ? warn_on_whitespace
  91                                   : nowarn_whitespace);
  92         }
  93 }
  94
  95 /*
  96  * For "diff-stat" like behaviour, we keep track of the biggest change
  97  * we've seen, and the longest filename. That allows us to do simple
  98  * scaling.
  99  */
 100 static int max_change, max_len;
 101
 102 /*
 103  * Various "current state", notably line numbers and what
 104  * file (and how) we're patching right now.. The "is_xxxx"
 105  * things are flags, where -1 means "don't know yet".
 106  */
 107 static int linenr = 1;
 108
 109 struct fragment {
 110         unsigned long leading, trailing;
 111         unsigned long oldpos, oldlines;
 112         unsigned long newpos, newlines;
 113         const char *patch;
 114         int size;
 115         struct fragment *next;
 116 };
 117
 118 struct patch {
 119         char *new_name, *old_name, *def_name;
 120         unsigned int old_mode, new_mode;
 121         int is_rename, is_copy, is_new, is_delete, is_binary;
 122 #define BINARY_DELTA_DEFLATED 1
 123 #define BINARY_LITERAL_DEFLATED 2
 124         unsigned long deflate_origlen;
 125         int lines_added, lines_deleted;
 126         int score;
 127         struct fragment *fragments;
 128         char *result;
 129         unsigned long resultsize;
 130         char old_sha1_prefix[41];
 131         char new_sha1_prefix[41];
 132         struct patch *next;
 133 };
 134
 135 #define CHUNKSIZE (8192)
 136 #define SLOP (16)
 137
 138 static void *read_patch_file(int fd, unsigned long *sizep)
 139 {
 140         unsigned long size = 0, alloc = CHUNKSIZE;
 141         void *buffer = xmalloc(alloc);
 142
 143         for (;;) {
 144                 int nr = alloc - size;
 145                 if (nr < 1024) {
 146                         alloc += CHUNKSIZE;
 147                         buffer = xrealloc(buffer, alloc);
 148                         nr = alloc - size;
 149                 }
 150                 nr = xread(fd, buffer + size, nr);
 151                 if (!nr)
 152                         break;
 153                 if (nr < 0)
 154                         die("git-apply: read returned %s", strerror(errno));
 155                 size += nr;
 156         }
 157         *sizep = size;
 158
 159         /*
 160          * Make sure that we have some slop in the buffer
 161          * so that we can do speculative "memcmp" etc, and
 162          * see to it that it is NUL-filled.
 163          */
 164         if (alloc < size + SLOP)
 165                 buffer = xrealloc(buffer, size + SLOP);
 166         memset(buffer + size, 0, SLOP);
 167         return buffer;
 168 }
 169
 170 static unsigned long linelen(const char *buffer, unsigned long size)
 171 {
 172         unsigned long len = 0;
 173         while (size--) {
 174                 len++;
 175                 if (*buffer++ == '\n')
 176                         break;
 177         }
 178         return len;
 179 }
 180
 181 static int is_dev_null(const char *str)
 182 {
 183         return !memcmp("/dev/null", str, 9) && isspace(str[9]);
 184 }
 185
 186 #define TERM_SPACE      1
 187 #define TERM_TAB        2
 188
 189 static int name_terminate(const char *name, int namelen, int c, int terminate)
 190 {
 191         if (c == ' ' && !(terminate & TERM_SPACE))
 192                 return 0;
 193         if (c == '\t' && !(terminate & TERM_TAB))
 194                 return 0;
 195
 196         return 1;
 197 }
 198
 199 static char * find_name(const char *line, char *def, int p_value, int terminate)
 200 {
 201         int len;
 202         const char *start = line;
 203         char *name;
 204
 205         if (*line == '"') {
 206                 /* Proposed "new-style" GNU patch/diff format; see
 207                  * http://marc.theaimsgroup.com/?l=git&m=112927316408690&w=2
 208                  */
 209                 name = unquote_c_style(line, NULL);
 210                 if (name) {
 211                         char *cp = name;
 212                         while (p_value) {
 213                                 cp = strchr(name, '/');
 214                                 if (!cp)
 215                                         break;
 216                                 cp++;
 217                                 p_value--;
 218                         }
 219                         if (cp) {
 220                                 /* name can later be freed, so we need
 221                                  * to memmove, not just return cp
 222                                  */
 223                                 memmove(name, cp, strlen(cp) + 1);
 224                                 free(def);
 225                                 return name;
 226                         }
 227                         else {
 228                                 free(name);
 229                                 name = NULL;
 230                         }
 231                 }
 232         }
 233
 234         for (;;) {
 235                 char c = *line;
 236
 237                 if (isspace(c)) {
 238                         if (c == '\n')
 239                                 break;
 240                         if (name_terminate(start, line-start, c, terminate))
 241                                 break;
 242                 }
 243                 line++;
 244                 if (c == '/' && !--p_value)
 245                         start = line;
 246         }
 247         if (!start)
 248                 return def;
 249         len = line - start;
 250         if (!len)
 251                 return def;
 252
 253         /*
 254          * Generally we prefer the shorter name, especially
 255          * if the other one is just a variation of that with
 256          * something else tacked on to the end (ie "file.orig"
 257          * or "file~").
 258          */
 259         if (def) {
 260                 int deflen = strlen(def);
 261                 if (deflen < len && !strncmp(start, def, deflen))
 262                         return def;
 263         }
 264
 265         name = xmalloc(len + 1);
 266         memcpy(name, start, len);
 267         name[len] = 0;
 268         free(def);
 269         return name;
 270 }
 271
 272 /*
 273  * Get the name etc info from the --/+++ lines of a traditional patch header
 274  *
 275  * NOTE! This hardcodes "-p1" behaviour in filename detection.
 276  *
 277  * FIXME! The end-of-filename heuristics are kind of screwy. For existing
 278  * files, we can happily check the index for a match, but for creating a
 279  * new file we should try to match whatever "patch" does. I have no idea.
 280  */
 281 static void parse_traditional_patch(const char *first, const char *second, struct patch *patch)
 282 {
 283         char *name;
 284
 285         first += 4;     // skip "--- "
 286         second += 4;    // skip "+++ "
 287         if (is_dev_null(first)) {
 288                 patch->is_new = 1;
 289                 patch->is_delete = 0;
 290                 name = find_name(second, NULL, p_value, TERM_SPACE | TERM_TAB);
 291                 patch->new_name = name;
 292         } else if (is_dev_null(second)) {
 293                 patch->is_new = 0;
 294                 patch->is_delete = 1;
 295                 name = find_name(first, NULL, p_value, TERM_SPACE | TERM_TAB);
 296                 patch->old_name = name;
 297         } else {
 298                 name = find_name(first, NULL, p_value, TERM_SPACE | TERM_TAB);
 299                 name = find_name(second, name, p_value, TERM_SPACE | TERM_TAB);
 300                 patch->old_name = patch->new_name = name;
 301         }
 302         if (!name)
 303                 die("unable to find filename in patch at line %d", linenr);
 304 }
 305
 306 static int gitdiff_hdrend(const char *line, struct patch *patch)
 307 {
 308         return -1;
 309 }
 310
 311 /*
 312  * We're anal about diff header consistency, to make
 313  * sure that we don't end up having strange ambiguous
 314  * patches floating around.
 315  *
 316  * As a result, gitdiff_{old|new}name() will check
 317  * their names against any previous information, just
 318  * to make sure..
 319  */
 320 static char *gitdiff_verify_name(const char *line, int isnull, char *orig_name, const char *oldnew)
 321 {
 322         if (!orig_name && !isnull)
 323                 return find_name(line, NULL, 1, 0);
 324
 325         if (orig_name) {
 326                 int len;
 327                 const char *name;
 328                 char *another;
 329                 name = orig_name;
 330                 len = strlen(name);
 331                 if (isnull)
 332                         die("git-apply: bad git-diff - expected /dev/null, got %s on line %d", name, linenr);
 333                 another = find_name(line, NULL, 1, 0);
 334                 if (!another || memcmp(another, name, len))
 335                         die("git-apply: bad git-diff - inconsistent %s filename on line %d", oldnew, linenr);
 336                 free(another);
 337                 return orig_name;
 338         }
 339         else {
 340                 /* expect "/dev/null" */
 341                 if (memcmp("/dev/null", line, 9) || line[9] != '\n')
 342                         die("git-apply: bad git-diff - expected /dev/null on line %d", linenr);
 343                 return NULL;
 344         }
 345 }
 346
 347 static int gitdiff_oldname(const char *line, struct patch *patch)
 348 {
 349         patch->old_name = gitdiff_verify_name(line, patch->is_new, patch->old_name, "old");
 350         return 0;
 351 }
 352
 353 static int gitdiff_newname(const char *line, struct patch *patch)
 354 {
 355         patch->new_name = gitdiff_verify_name(line, patch->is_delete, patch->new_name, "new");
 356         return 0;
 357 }
 358
 359 static int gitdiff_oldmode(const char *line, struct patch *patch)
 360 {
 361         patch->old_mode = strtoul(line, NULL, 8);
 362         return 0;
 363 }
 364
 365 static int gitdiff_newmode(const char *line, struct patch *patch)
 366 {
 367         patch->new_mode = strtoul(line, NULL, 8);
 368         return 0;
 369 }
 370
 371 static int gitdiff_delete(const char *line, struct patch *patch)
 372 {
 373         patch->is_delete = 1;
 374         patch->old_name = patch->def_name;
 375         return gitdiff_oldmode(line, patch);
 376 }
 377
 378 static int gitdiff_newfile(const char *line, struct patch *patch)
 379 {
 380         patch->is_new = 1;
 381         patch->new_name = patch->def_name;
 382         return gitdiff_newmode(line, patch);
 383 }
 384
 385 static int gitdiff_copysrc(const char *line, struct patch *patch)
 386 {
 387         patch->is_copy = 1;
 388         patch->old_name = find_name(line, NULL, 0, 0);
 389         return 0;
 390 }
 391
 392 static int gitdiff_copydst(const char *line, struct patch *patch)
 393 {
 394         patch->is_copy = 1;
 395         patch->new_name = find_name(line, NULL, 0, 0);
 396         return 0;
 397 }
 398
 399 static int gitdiff_renamesrc(const char *line, struct patch *patch)
 400 {
 401         patch->is_rename = 1;
 402         patch->old_name = find_name(line, NULL, 0, 0);
 403         return 0;
 404 }
 405
 406 static int gitdiff_renamedst(const char *line, struct patch *patch)
 407 {
 408         patch->is_rename = 1;
 409         patch->new_name = find_name(line, NULL, 0, 0);
 410         return 0;
 411 }
 412
 413 static int gitdiff_similarity(const char *line, struct patch *patch)
 414 {
 415         if ((patch->score = strtoul(line, NULL, 10)) == ULONG_MAX)
 416                 patch->score = 0;
 417         return 0;
 418 }
 419
 420 static int gitdiff_dissimilarity(const char *line, struct patch *patch)
 421 {
 422         if ((patch->score = strtoul(line, NULL, 10)) == ULONG_MAX)
 423                 patch->score = 0;
 424         return 0;
 425 }
 426
 427 static int gitdiff_index(const char *line, struct patch *patch)
 428 {
 429         /* index line is N hexadecimal, "..", N hexadecimal,
 430          * and optional space with octal mode.
 431          */
 432         const char *ptr, *eol;
 433         int len;
 434
 435         ptr = strchr(line, '.');
 436         if (!ptr || ptr[1] != '.' || 40 < ptr - line)
 437                 return 0;
 438         len = ptr - line;
 439         memcpy(patch->old_sha1_prefix, line, len);
 440         patch->old_sha1_prefix[len] = 0;
 441
 442         line = ptr + 2;
 443         ptr = strchr(line, ' ');
 444         eol = strchr(line, '\n');
 445
 446         if (!ptr || eol < ptr)
 447                 ptr = eol;
 448         len = ptr - line;
 449
 450         if (40 < len)
 451                 return 0;
 452         memcpy(patch->new_sha1_prefix, line, len);
 453         patch->new_sha1_prefix[len] = 0;
 454         if (*ptr == ' ')
 455                 patch->new_mode = patch->old_mode = strtoul(ptr+1, NULL, 8);
 456         return 0;
 457 }
 458
 459 /*
 460  * This is normal for a diff that doesn't change anything: we'll fall through
 461  * into the next diff. Tell the parser to break out.
 462  */
 463 static int gitdiff_unrecognized(const char *line, struct patch *patch)
 464 {
 465         return -1;
 466 }
 467
 468 static const char *stop_at_slash(const char *line, int llen)
 469 {
 470         int i;
 471
 472         for (i = 0; i < llen; i++) {
 473                 int ch = line[i];
 474                 if (ch == '/')
 475                         return line + i;
 476         }
 477         return NULL;
 478 }
 479
 480 /* This is to extract the same name that appears on "diff --git"
 481  * line.  We do not find and return anything if it is a rename
 482  * patch, and it is OK because we will find the name elsewhere.
 483  * We need to reliably find name only when it is mode-change only,
 484  * creation or deletion of an empty file.  In any of these cases,
 485  * both sides are the same name under a/ and b/ respectively.
 486  */
 487 static char *git_header_name(char *line, int llen)
 488 {
 489         int len;
 490         const char *name;
 491         const char *second = NULL;
 492
 493         line += strlen("diff --git ");
 494         llen -= strlen("diff --git ");
 495
 496         if (*line == '"') {
 497                 const char *cp;
 498                 char *first = unquote_c_style(line, &second);
 499                 if (!first)
 500                         return NULL;
 501
 502                 /* advance to the first slash */
 503                 cp = stop_at_slash(first, strlen(first));
 504                 if (!cp || cp == first) {
 505                         /* we do not accept absolute paths */
 506                 free_first_and_fail:
 507                         free(first);
 508                         return NULL;
 509                 }
 510                 len = strlen(cp+1);
 511                 memmove(first, cp+1, len+1); /* including NUL */
 512
 513                 /* second points at one past closing dq of name.
 514                  * find the second name.
 515                  */
 516                 while ((second < line + llen) && isspace(*second))
 517                         second++;
 518
 519                 if (line + llen <= second)
 520                         goto free_first_and_fail;
 521                 if (*second == '"') {
 522                         char *sp = unquote_c_style(second, NULL);
 523                         if (!sp)
 524                                 goto free_first_and_fail;
 525                         cp = stop_at_slash(sp, strlen(sp));
 526                         if (!cp || cp == sp) {
 527                         free_both_and_fail:
 528                                 free(sp);
 529                                 goto free_first_and_fail;
 530                         }
 531                         /* They must match, otherwise ignore */
 532                         if (strcmp(cp+1, first))
 533                                 goto free_both_and_fail;
 534                         free(sp);
 535                         return first;
 536                 }
 537
 538                 /* unquoted second */
 539                 cp = stop_at_slash(second, line + llen - second);
 540                 if (!cp || cp == second)
 541                         goto free_first_and_fail;
 542                 cp++;
 543                 if (line + llen - cp != len + 1 ||
 544                     memcmp(first, cp, len))
 545                         goto free_first_and_fail;
 546                 return first;
 547         }
 548
 549         /* unquoted first name */
 550         name = stop_at_slash(line, llen);
 551         if (!name || name == line)
 552                 return NULL;
 553
 554         name++;
 555
 556         /* since the first name is unquoted, a dq if exists must be
 557          * the beginning of the second name.
 558          */
 559         for (second = name; second < line + llen; second++) {
 560                 if (*second == '"') {
 561                         const char *cp = second;
 562                         const char *np;
 563                         char *sp = unquote_c_style(second, NULL);
 564
 565                         if (!sp)
 566                                 return NULL;
 567                         np = stop_at_slash(sp, strlen(sp));
 568                         if (!np || np == sp) {
 569                         free_second_and_fail:
 570                                 free(sp);
 571                                 return NULL;
 572                         }
 573                         np++;
 574                         len = strlen(np);
 575                         if (len < cp - name &&
 576                             !strncmp(np, name, len) &&
 577                             isspace(name[len])) {
 578                                 /* Good */
 579                                 memmove(sp, np, len + 1);
 580                                 return sp;
 581                         }
 582                         goto free_second_and_fail;
 583                 }
 584         }
 585
 586         /*
 587          * Accept a name only if it shows up twice, exactly the same
 588          * form.
 589          */
 590         for (len = 0 ; ; len++) {
 591                 char c = name[len];
 592
 593                 switch (c) {
 594                 default:
 595                         continue;
 596                 case '\n':
 597                         return NULL;
 598                 case '\t': case ' ':
 599                         second = name+len;
 600                         for (;;) {
 601                                 char c = *second++;
 602                                 if (c == '\n')
 603                                         return NULL;
 604                                 if (c == '/')
 605                                         break;
 606                         }
 607                         if (second[len] == '\n' && !memcmp(name, second, len)) {
 608                                 char *ret = xmalloc(len + 1);
 609                                 memcpy(ret, name, len);
 610                                 ret[len] = 0;
 611                                 return ret;
 612                         }
 613                 }
 614         }
 615         return NULL;
 616 }
 617
 618 /* Verify that we recognize the lines following a git header */
 619 static int parse_git_header(char *line, int len, unsigned int size, struct patch *patch)
 620 {
 621         unsigned long offset;
 622
 623         /* A git diff has explicit new/delete information, so we don't guess */
 624         patch->is_new = 0;
 625         patch->is_delete = 0;
 626
 627         /*
 628          * Some things may not have the old name in the
 629          * rest of the headers anywhere (pure mode changes,
 630          * or removing or adding empty files), so we get
 631          * the default name from the header.
 632          */
 633         patch->def_name = git_header_name(line, len);
 634
 635         line += len;
 636         size -= len;
 637         linenr++;
 638         for (offset = len ; size > 0 ; offset += len, size -= len, line += len, linenr++) {
 639                 static const struct opentry {
 640                         const char *str;
 641                         int (*fn)(const char *, struct patch *);
 642                 } optable[] = {
 643                         { "@@ -", gitdiff_hdrend },
 644                         { "--- ", gitdiff_oldname },
 645                         { "+++ ", gitdiff_newname },
 646                         { "old mode ", gitdiff_oldmode },
 647                         { "new mode ", gitdiff_newmode },
 648                         { "deleted file mode ", gitdiff_delete },
 649                         { "new file mode ", gitdiff_newfile },
 650                         { "copy from ", gitdiff_copysrc },
 651                         { "copy to ", gitdiff_copydst },
 652                         { "rename old ", gitdiff_renamesrc },
 653                         { "rename new ", gitdiff_renamedst },
 654                         { "rename from ", gitdiff_renamesrc },
 655                         { "rename to ", gitdiff_renamedst },
 656                         { "similarity index ", gitdiff_similarity },
 657                         { "dissimilarity index ", gitdiff_dissimilarity },
 658                         { "index ", gitdiff_index },
 659                         { "", gitdiff_unrecognized },
 660                 };
 661                 int i;
 662
 663                 len = linelen(line, size);
 664                 if (!len || line[len-1] != '\n')
 665                         break;
 666                 for (i = 0; i < ARRAY_SIZE(optable); i++) {
 667                         const struct opentry *p = optable + i;
 668                         int oplen = strlen(p->str);
 669                         if (len < oplen || memcmp(p->str, line, oplen))
 670                                 continue;
 671                         if (p->fn(line + oplen, patch) < 0)
 672                                 return offset;
 673                         break;
 674                 }
 675         }
 676
 677         return offset;
 678 }
 679
 680 static int parse_num(const char *line, unsigned long *p)
 681 {
 682         char *ptr;
 683
 684         if (!isdigit(*line))
 685                 return 0;
 686         *p = strtoul(line, &ptr, 10);
 687         return ptr - line;
 688 }
 689
 690 static int parse_range(const char *line, int len, int offset, const char *expect,
 691                         unsigned long *p1, unsigned long *p2)
 692 {
 693         int digits, ex;
 694
 695         if (offset < 0 || offset >= len)
 696                 return -1;
 697         line += offset;
 698         len -= offset;
 699
 700         digits = parse_num(line, p1);
 701         if (!digits)
 702                 return -1;
 703
 704         offset += digits;
 705         line += digits;
 706         len -= digits;
 707
 708         *p2 = 1;
 709         if (*line == ',') {
 710                 digits = parse_num(line+1, p2);
 711                 if (!digits)
 712                         return -1;
 713
 714                 offset += digits+1;
 715                 line += digits+1;
 716                 len -= digits+1;
 717         }
 718
 719         ex = strlen(expect);
 720         if (ex > len)
 721                 return -1;
 722         if (memcmp(line, expect, ex))
 723                 return -1;
 724
 725         return offset + ex;
 726 }
 727
 728 /*
 729  * Parse a unified diff fragment header of the
 730  * form "@@ -a,b +c,d @@"
 731  */
 732 static int parse_fragment_header(char *line, int len, struct fragment *fragment)
 733 {
 734         int offset;
 735
 736         if (!len || line[len-1] != '\n')
 737                 return -1;
 738
 739         /* Figure out the number of lines in a fragment */
 740         offset = parse_range(line, len, 4, " +", &fragment->oldpos, &fragment->oldlines);
 741         offset = parse_range(line, len, offset, " @@", &fragment->newpos, &fragment->newlines);
 742
 743         return offset;
 744 }
 745
 746 static int find_header(char *line, unsigned long size, int *hdrsize, struct patch *patch)
 747 {
 748         unsigned long offset, len;
 749
 750         patch->is_rename = patch->is_copy = 0;
 751         patch->is_new = patch->is_delete = -1;
 752         patch->old_mode = patch->new_mode = 0;
 753         patch->old_name = patch->new_name = NULL;
 754         for (offset = 0; size > 0; offset += len, size -= len, line += len, linenr++) {
 755                 unsigned long nextlen;
 756
 757                 len = linelen(line, size);
 758                 if (!len)
 759                         break;
 760
 761                 /* Testing this early allows us to take a few shortcuts.. */
 762                 if (len < 6)
 763                         continue;
 764
 765                 /*
 766                  * Make sure we don't find any unconnected patch fragmants.
 767                  * That's a sign that we didn't find a header, and that a
 768                  * patch has become corrupted/broken up.
 769                  */
 770                 if (!memcmp("@@ -", line, 4)) {
 771                         struct fragment dummy;
 772                         if (parse_fragment_header(line, len, &dummy) < 0)
 773                                 continue;
 774                         error("patch fragment without header at line %d: %.*s", linenr, (int)len-1, line);
 775                 }
 776
 777                 if (size < len + 6)
 778                         break;
 779
 780                 /*
 781                  * Git patch? It might not have a real patch, just a rename
 782                  * or mode change, so we handle that specially
 783                  */
 784                 if (!memcmp("diff --git ", line, 11)) {
 785                         int git_hdr_len = parse_git_header(line, len, size, patch);
 786                         if (git_hdr_len <= len)
 787                                 continue;
 788                         if (!patch->old_name && !patch->new_name) {
 789                                 if (!patch->def_name)
 790                                         die("git diff header lacks filename information (line %d)", linenr);
 791                                 patch->old_name = patch->new_name = patch->def_name;
 792                         }
 793                         *hdrsize = git_hdr_len;
 794                         return offset;
 795                 }
 796
 797                 /** --- followed by +++ ? */
 798                 if (memcmp("--- ", line,  4) || memcmp("+++ ", line + len, 4))
 799                         continue;
 800
 801                 /*
 802                  * We only accept unified patches, so we want it to
 803                  * at least have "@@ -a,b +c,d @@\n", which is 14 chars
 804                  * minimum
 805                  */
 806                 nextlen = linelen(line + len, size - len);
 807                 if (size < nextlen + 14 || memcmp("@@ -", line + len + nextlen, 4))
 808                         continue;
 809
 810                 /* Ok, we'll consider it a patch */
 811                 parse_traditional_patch(line, line+len, patch);
 812                 *hdrsize = len + nextlen;
 813                 linenr += 2;
 814                 return offset;
 815         }
 816         return -1;
 817 }
 818
 819 /*
 820  * Parse a unified diff. Note that this really needs
 821  * to parse each fragment separately, since the only
 822  * way to know the difference between a "---" that is
 823  * part of a patch, and a "---" that starts the next
 824  * patch is to look at the line counts..
 825  */
 826 static int parse_fragment(char *line, unsigned long size, struct patch *patch, struct fragment *fragment)
 827 {
 828         int added, deleted;
 829         int len = linelen(line, size), offset;
 830         unsigned long oldlines, newlines;
 831         unsigned long leading, trailing;
 832
 833         offset = parse_fragment_header(line, len, fragment);
 834         if (offset < 0)
 835                 return -1;
 836         oldlines = fragment->oldlines;
 837         newlines = fragment->newlines;
 838         leading = 0;
 839         trailing = 0;
 840
 841         if (patch->is_new < 0) {
 842                 patch->is_new =  !oldlines;
 843                 if (!oldlines)
 844                         patch->old_name = NULL;
 845         }
 846         if (patch->is_delete < 0) {
 847                 patch->is_delete = !newlines;
 848                 if (!newlines)
 849                         patch->new_name = NULL;
 850         }
 851
 852         if (patch->is_new && oldlines)
 853                 return error("new file depends on old contents");
 854         if (patch->is_delete != !newlines) {
 855                 if (newlines)
 856                         return error("deleted file still has contents");
 857                 fprintf(stderr, "** warning: file %s becomes empty but is not deleted\n", patch->new_name);
 858         }
 859
 860         /* Parse the thing.. */
 861         line += len;
 862         size -= len;
 863         linenr++;
 864         added = deleted = 0;
 865         for (offset = len; size > 0; offset += len, size -= len, line += len, linenr++) {
 866                 if (!oldlines && !newlines)
 867                         break;
 868                 len = linelen(line, size);
 869                 if (!len || line[len-1] != '\n')
 870                         return -1;
 871                 switch (*line) {
 872                 default:
 873                         return -1;
 874                 case ' ':
 875                         oldlines--;
 876                         newlines--;
 877                         if (!deleted && !added)
 878                                 leading++;
 879                         trailing++;
 880                         break;
 881                 case '-':
 882                         deleted++;
 883                         oldlines--;
 884                         trailing = 0;
 885                         break;
 886                 case '+':
 887                         /*
 888                          * We know len is at least two, since we have a '+' and
 889                          * we checked that the last character was a '\n' above.
 890                          * That is, an addition of an empty line would check
 891                          * the '+' here.  Sneaky...
 892                          */
 893                         if ((new_whitespace != nowarn_whitespace) &&
 894                             isspace(line[len-2])) {
 895                                 whitespace_error++;
 896                                 if (squelch_whitespace_errors &&
 897                                     squelch_whitespace_errors <
 898                                     whitespace_error)
 899                                         ;
 900                                 else {
 901                                         fprintf(stderr, "Adds trailing whitespace.\n%s:%d:%.*s\n",
 902                                                 patch_input_file,
 903                                                 linenr, len-2, line+1);
 904                                 }
 905                         }
 906                         added++;
 907                         newlines--;
 908                         trailing = 0;
 909                         break;
 910
 911                 /* We allow "\ No newline at end of file". Depending
 912                  * on locale settings when the patch was produced we
 913                  * don't know what this line looks like. The only
 914                  * thing we do know is that it begins with "\ ".
 915                  * Checking for 12 is just for sanity check -- any
 916                  * l10n of "\ No newline..." is at least that long.
 917                  */
 918                 case '\\':
 919                         if (len < 12 || memcmp(line, "\\ ", 2))
 920                                 return -1;
 921                         break;
 922                 }
 923         }
 924         if (oldlines || newlines)
 925                 return -1;
 926         fragment->leading = leading;
 927         fragment->trailing = trailing;
 928
 929         /* If a fragment ends with an incomplete line, we failed to include
 930          * it in the above loop because we hit oldlines == newlines == 0
 931          * before seeing it.
 932          */
 933         if (12 < size && !memcmp(line, "\\ ", 2))
 934                 offset += linelen(line, size);
 935
 936         patch->lines_added += added;
 937         patch->lines_deleted += deleted;
 938         return offset;
 939 }
 940
 941 static int parse_single_patch(char *line, unsigned long size, struct patch *patch)
 942 {
 943         unsigned long offset = 0;
 944         struct fragment **fragp = &patch->fragments;
 945
 946         while (size > 4 && !memcmp(line, "@@ -", 4)) {
 947                 struct fragment *fragment;
 948                 int len;
 949
 950                 fragment = xcalloc(1, sizeof(*fragment));
 951                 len = parse_fragment(line, size, patch, fragment);
 952                 if (len <= 0)
 953                         die("corrupt patch at line %d", linenr);
 954
 955                 fragment->patch = line;
 956                 fragment->size = len;
 957
 958                 *fragp = fragment;
 959                 fragp = &fragment->next;
 960
 961                 offset += len;
 962                 line += len;
 963                 size -= len;
 964         }
 965         return offset;
 966 }
 967
 968 static inline int metadata_changes(struct patch *patch)
 969 {
 970         return  patch->is_rename > 0 ||
 971                 patch->is_copy > 0 ||
 972                 patch->is_new > 0 ||
 973                 patch->is_delete ||
 974                 (patch->old_mode && patch->new_mode &&
 975                  patch->old_mode != patch->new_mode);
 976 }
 977
 978 static int parse_binary(char *buffer, unsigned long size, struct patch *patch)
 979 {
 980         /* We have read "GIT binary patch\n"; what follows is a line
 981          * that says the patch method (currently, either "deflated
 982          * literal" or "deflated delta") and the length of data before
 983          * deflating; a sequence of 'length-byte' followed by base-85
 984          * encoded data follows.
 985          *
 986          * Each 5-byte sequence of base-85 encodes up to 4 bytes,
 987          * and we would limit the patch line to 66 characters,
 988          * so one line can fit up to 13 groups that would decode
 989          * to 52 bytes max.  The length byte 'A'-'Z' corresponds
 990          * to 1-26 bytes, and 'a'-'z' corresponds to 27-52 bytes.
 991          * The end of binary is signalled with an empty line.
 992          */
 993         int llen, used;
 994         struct fragment *fragment;
 995         char *data = NULL;
 996
 997         patch->fragments = fragment = xcalloc(1, sizeof(*fragment));
 998
 999         /* Grab the type of patch */
1000         llen = linelen(buffer, size);
1001         used = llen;
1002         linenr++;
1003
1004         if (!strncmp(buffer, "delta ", 6)) {
1005                 patch->is_binary = BINARY_DELTA_DEFLATED;
1006                 patch->deflate_origlen = strtoul(buffer + 6, NULL, 10);
1007         }
1008         else if (!strncmp(buffer, "literal ", 8)) {
1009                 patch->is_binary = BINARY_LITERAL_DEFLATED;
1010                 patch->deflate_origlen = strtoul(buffer + 8, NULL, 10);
1011         }
1012         else
1013                 return error("unrecognized binary patch at line %d: %.*s",
1014                              linenr-1, llen-1, buffer);
1015         buffer += llen;
1016         while (1) {
1017                 int byte_length, max_byte_length, newsize;
1018                 llen = linelen(buffer, size);
1019                 used += llen;
1020                 linenr++;
1021                 if (llen == 1)
1022                         break;
1023                 /* Minimum line is "A00000\n" which is 7-byte long,
1024                  * and the line length must be multiple of 5 plus 2.
1025                  */
1026                 if ((llen < 7) || (llen-2) % 5)
1027                         goto corrupt;
1028                 max_byte_length = (llen - 2) / 5 * 4;
1029                 byte_length = *buffer;
1030                 if ('A' <= byte_length && byte_length <= 'Z')
1031                         byte_length = byte_length - 'A' + 1;
1032                 else if ('a' <= byte_length && byte_length <= 'z')
1033                         byte_length = byte_length - 'a' + 27;
1034                 else
1035                         goto corrupt;
1036                 /* if the input length was not multiple of 4, we would
1037                  * have filler at the end but the filler should never
1038                  * exceed 3 bytes
1039                  */
1040                 if (max_byte_length < byte_length ||
1041                     byte_length <= max_byte_length - 4)
1042                         goto corrupt;
1043                 newsize = fragment->size + byte_length;
1044                 data = xrealloc(data, newsize);
1045                 if (decode_85(data + fragment->size,
1046                               buffer + 1,
1047                               byte_length))
1048                         goto corrupt;
1049                 fragment->size = newsize;
1050                 buffer += llen;
1051                 size -= llen;
1052         }
1053         fragment->patch = data;
1054         return used;
1055  corrupt:
1056         return error("corrupt binary patch at line %d: %.*s",
1057                      linenr-1, llen-1, buffer);
1058 }
1059
1060 static int parse_chunk(char *buffer, unsigned long size, struct patch *patch)
1061 {
1062         int hdrsize, patchsize;
1063         int offset = find_header(buffer, size, &hdrsize, patch);
1064
1065         if (offset < 0)
1066                 return offset;
1067
1068         patchsize = parse_single_patch(buffer + offset + hdrsize, size - offset - hdrsize, patch);
1069
1070         if (!patchsize) {
1071                 static const char *binhdr[] = {
1072                         "Binary files ",
1073                         "Files ",
1074                         NULL,
1075                 };
1076                 static const char git_binary[] = "GIT binary patch\n";
1077                 int i;
1078                 int hd = hdrsize + offset;
1079                 unsigned long llen = linelen(buffer + hd, size - hd);
1080
1081                 if (llen == sizeof(git_binary) - 1 &&
1082                     !memcmp(git_binary, buffer + hd, llen)) {
1083                         int used;
1084                         linenr++;
1085                         used = parse_binary(buffer + hd + llen,
1086                                             size - hd - llen, patch);
1087                         if (used)
1088                                 patchsize = used + llen;
1089                         else
1090                                 patchsize = 0;
1091                 }
1092                 else if (!memcmp(" differ\n", buffer + hd + llen - 8, 8)) {
1093                         for (i = 0; binhdr[i]; i++) {
1094                                 int len = strlen(binhdr[i]);
1095                                 if (len < size - hd &&
1096                                     !memcmp(binhdr[i], buffer + hd, len)) {
1097                                         linenr++;
1098                                         patch->is_binary = 1;
1099                                         patchsize = llen;
1100                                         break;
1101                                 }
1102                         }
1103                 }
1104
1105                 /* Empty patch cannot be applied if:
1106                  * - it is a binary patch and we do not do binary_replace, or
1107                  * - text patch without metadata change
1108                  */
1109                 if ((apply || check) &&
1110                     (patch->is_binary
1111                      ? !allow_binary_replacement
1112                      : !metadata_changes(patch)))
1113                         die("patch with only garbage at line %d", linenr);
1114         }
1115
1116         return offset + hdrsize + patchsize;
1117 }
1118
1119 static const char pluses[] = "++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++";
1120 static const char minuses[]= "----------------------------------------------------------------------";
1121
1122 static void show_stats(struct patch *patch)
1123 {
1124         const char *prefix = "";
1125         char *name = patch->new_name;
1126         char *qname = NULL;
1127         int len, max, add, del, total;
1128
1129         if (!name)
1130                 name = patch->old_name;
1131
1132         if (0 < (len = quote_c_style(name, NULL, NULL, 0))) {
1133                 qname = xmalloc(len + 1);
1134                 quote_c_style(name, qname, NULL, 0);
1135                 name = qname;
1136         }
1137
1138         /*
1139          * "scale" the filename
1140          */
1141         len = strlen(name);
1142         max = max_len;
1143         if (max > 50)
1144                 max = 50;
1145         if (len > max) {
1146                 char *slash;
1147                 prefix = "...";
1148                 max -= 3;
1149                 name += len - max;
1150                 slash = strchr(name, '/');
1151                 if (slash)
1152                         name = slash;
1153         }
1154         len = max;
1155
1156         /*
1157          * scale the add/delete
1158          */
1159         max = max_change;
1160         if (max + len > 70)
1161                 max = 70 - len;
1162
1163         add = patch->lines_added;
1164         del = patch->lines_deleted;
1165         total = add + del;
1166
1167         if (max_change > 0) {
1168                 total = (total * max + max_change / 2) / max_change;
1169                 add = (add * max + max_change / 2) / max_change;
1170                 del = total - add;
1171         }
1172         if (patch->is_binary)
1173                 printf(" %s%-*s |  Bin\n", prefix, len, name);
1174         else
1175                 printf(" %s%-*s |%5d %.*s%.*s\n", prefix,
1176                        len, name, patch->lines_added + patch->lines_deleted,
1177                        add, pluses, del, minuses);
1178         if (qname)
1179                 free(qname);
1180 }
1181
1182 static int read_old_data(struct stat *st, const char *path, void *buf, unsigned long size)
1183 {
1184         int fd;
1185         unsigned long got;
1186
1187         switch (st->st_mode & S_IFMT) {
1188         case S_IFLNK:
1189                 return readlink(path, buf, size);
1190         case S_IFREG:
1191                 fd = open(path, O_RDONLY);
1192                 if (fd < 0)
1193                         return error("unable to open %s", path);
1194                 got = 0;
1195                 for (;;) {
1196                         int ret = xread(fd, buf + got, size - got);
1197                         if (ret <= 0)
1198                                 break;
1199                         got += ret;
1200                 }
1201                 close(fd);
1202                 return got;
1203
1204         default:
1205                 return -1;
1206         }
1207 }
1208
1209 static int find_offset(const char *buf, unsigned long size, const char *fragment, unsigned long fragsize, int line, int *lines)
1210 {
1211         int i;
1212         unsigned long start, backwards, forwards;
1213
1214         if (fragsize > size)
1215                 return -1;
1216
1217         start = 0;
1218         if (line > 1) {
1219                 unsigned long offset = 0;
1220                 i = line-1;
1221                 while (offset + fragsize <= size) {
1222                         if (buf[offset++] == '\n') {
1223                                 start = offset;
1224                                 if (!--i)
1225                                         break;
1226                         }
1227                 }
1228         }
1229
1230         /* Exact line number? */
1231         if (!memcmp(buf + start, fragment, fragsize))
1232                 return start;
1233
1234         /*
1235          * There's probably some smart way to do this, but I'll leave
1236          * that to the smart and beautiful people. I'm simple and stupid.
1237          */
1238         backwards = start;
1239         forwards = start;
1240         for (i = 0; ; i++) {
1241                 unsigned long try;
1242                 int n;
1243
1244                 /* "backward" */
1245                 if (i & 1) {
1246                         if (!backwards) {
1247                                 if (forwards + fragsize > size)
1248                                         break;
1249                                 continue;
1250                         }
1251                         do {
1252                                 --backwards;
1253                         } while (backwards && buf[backwards-1] != '\n');
1254                         try = backwards;
1255                 } else {
1256                         while (forwards + fragsize <= size) {
1257                                 if (buf[forwards++] == '\n')
1258                                         break;
1259                         }
1260                         try = forwards;
1261                 }
1262
1263                 if (try + fragsize > size)
1264                         continue;
1265                 if (memcmp(buf + try, fragment, fragsize))
1266                         continue;
1267                 n = (i >> 1)+1;
1268                 if (i & 1)
1269                         n = -n;
1270                 *lines = n;
1271                 return try;
1272         }
1273
1274         /*
1275          * We should start searching forward and backward.
1276          */
1277         return -1;
1278 }
1279
1280 static void remove_first_line(const char **rbuf, int *rsize)
1281 {
1282         const char *buf = *rbuf;
1283         int size = *rsize;
1284         unsigned long offset;
1285         offset = 0;
1286         while (offset <= size) {
1287                 if (buf[offset++] == '\n')
1288                         break;
1289         }
1290         *rsize = size - offset;
1291         *rbuf = buf + offset;
1292 }
1293
1294 static void remove_last_line(const char **rbuf, int *rsize)
1295 {
1296         const char *buf = *rbuf;
1297         int size = *rsize;
1298         unsigned long offset;
1299         offset = size - 1;
1300         while (offset > 0) {
1301                 if (buf[--offset] == '\n')
1302                         break;
1303         }
1304         *rsize = offset + 1;
1305 }
1306
1307 struct buffer_desc {
1308         char *buffer;
1309         unsigned long size;
1310         unsigned long alloc;
1311 };
1312
1313 static int apply_line(char *output, const char *patch, int plen)
1314 {
1315         /* plen is number of bytes to be copied from patch,
1316          * starting at patch+1 (patch[0] is '+').  Typically
1317          * patch[plen] is '\n'.
1318          */
1319         int add_nl_to_tail = 0;
1320         if ((new_whitespace == strip_whitespace) &&
1321             1 < plen && isspace(patch[plen-1])) {
1322                 if (patch[plen] == '\n')
1323                         add_nl_to_tail = 1;
1324                 plen--;
1325                 while (0 < plen && isspace(patch[plen]))
1326                         plen--;
1327                 applied_after_stripping++;
1328         }
1329         memcpy(output, patch + 1, plen);
1330         if (add_nl_to_tail)
1331                 output[plen++] = '\n';
1332         return plen;
1333 }
1334
1335 static int apply_one_fragment(struct buffer_desc *desc, struct fragment *frag)
1336 {
1337         char *buf = desc->buffer;
1338         const char *patch = frag->patch;
1339         int offset, size = frag->size;
1340         char *old = xmalloc(size);
1341         char *new = xmalloc(size);
1342         const char *oldlines, *newlines;
1343         int oldsize = 0, newsize = 0;
1344         unsigned long leading, trailing;
1345         int pos, lines;
1346
1347         while (size > 0) {
1348                 int len = linelen(patch, size);
1349                 int plen;
1350
1351                 if (!len)
1352                         break;
1353
1354                 /*
1355                  * "plen" is how much of the line we should use for
1356                  * the actual patch data. Normally we just remove the
1357                  * first character on the line, but if the line is
1358                  * followed by "\ No newline", then we also remove the
1359                  * last one (which is the newline, of course).
1360                  */
1361                 plen = len-1;
1362                 if (len < size && patch[len] == '\\')
1363                         plen--;
1364                 switch (*patch) {
1365                 case ' ':
1366                 case '-':
1367                         memcpy(old + oldsize, patch + 1, plen);
1368                         oldsize += plen;
1369                         if (*patch == '-')
1370                                 break;
1371                 /* Fall-through for ' ' */
1372                 case '+':
1373                         if (*patch != '+' || !no_add)
1374                                 newsize += apply_line(new + newsize, patch,
1375                                                       plen);
1376                         break;
1377                 case '@': case '\\':
1378                         /* Ignore it, we already handled it */
1379                         break;
1380                 default:
1381                         return -1;
1382                 }
1383                 patch += len;
1384                 size -= len;
1385         }
1386
1387 #ifdef NO_ACCURATE_DIFF
1388         if (oldsize > 0 && old[oldsize - 1] == '\n' &&
1389                         newsize > 0 && new[newsize - 1] == '\n') {
1390                 oldsize--;
1391                 newsize--;
1392         }
1393 #endif
1394
1395         oldlines = old;
1396         newlines = new;
1397         leading = frag->leading;
1398         trailing = frag->trailing;
1399         lines = 0;
1400         pos = frag->newpos;
1401         for (;;) {
1402                 offset = find_offset(buf, desc->size, oldlines, oldsize, pos, &lines);
1403                 if (offset >= 0) {
1404                         int diff = newsize - oldsize;
1405                         unsigned long size = desc->size + diff;
1406                         unsigned long alloc = desc->alloc;
1407
1408                         /* Warn if it was necessary to reduce the number
1409                          * of context lines.
1410                          */
1411                         if ((leading != frag->leading) || (trailing != frag->trailing))
1412                                 fprintf(stderr, "Context reduced to (%ld/%ld) to apply fragment at %d\n",
1413                                         leading, trailing, pos + lines);
1414
1415                         if (size > alloc) {
1416                                 alloc = size + 8192;
1417                                 desc->alloc = alloc;
1418                                 buf = xrealloc(buf, alloc);
1419                                 desc->buffer = buf;
1420                         }
1421                         desc->size = size;
1422                         memmove(buf + offset + newsize, buf + offset + oldsize, size - offset - newsize);
1423                         memcpy(buf + offset, newlines, newsize);
1424                         offset = 0;
1425
1426                         break;
1427                 }
1428
1429                 /* Am I at my context limits? */
1430                 if ((leading <= p_context) && (trailing <= p_context))
1431                         break;
1432                 /* Reduce the number of context lines
1433                  * Reduce both leading and trailing if they are equal
1434                  * otherwise just reduce the larger context.
1435                  */
1436                 if (leading >= trailing) {
1437                         remove_first_line(&oldlines, &oldsize);
1438                         remove_first_line(&newlines, &newsize);
1439                         pos--;
1440                         leading--;
1441                 }
1442                 if (trailing > leading) {
1443                         remove_last_line(&oldlines, &oldsize);
1444                         remove_last_line(&newlines, &newsize);
1445                         trailing--;
1446                 }
1447         }
1448
1449         free(old);
1450         free(new);
1451         return offset;
1452 }
1453
1454 static char *inflate_it(const void *data, unsigned long size,
1455                         unsigned long inflated_size)
1456 {
1457         z_stream stream;
1458         void *out;
1459         int st;
1460
1461         memset(&stream, 0, sizeof(stream));
1462
1463         stream.next_in = (unsigned char *)data;
1464         stream.avail_in = size;
1465         stream.next_out = out = xmalloc(inflated_size);
1466         stream.avail_out = inflated_size;
1467         inflateInit(&stream);
1468         st = inflate(&stream, Z_FINISH);
1469         if ((st != Z_STREAM_END) || stream.total_out != inflated_size) {
1470                 free(out);
1471                 return NULL;
1472         }
1473         return out;
1474 }
1475
1476 static int apply_binary_fragment(struct buffer_desc *desc, struct patch *patch)
1477 {
1478         unsigned long dst_size;
1479         struct fragment *fragment = patch->fragments;
1480         void *data;
1481         void *result;
1482
1483         data = inflate_it(fragment->patch, fragment->size,
1484                           patch->deflate_origlen);
1485         if (!data)
1486                 return error("corrupt patch data");
1487         switch (patch->is_binary) {
1488         case BINARY_DELTA_DEFLATED:
1489                 result = patch_delta(desc->buffer, desc->size,
1490                                      data,
1491                                      patch->deflate_origlen,
1492                                      &dst_size);
1493                 free(desc->buffer);
1494                 desc->buffer = result;
1495                 free(data);
1496                 break;
1497         case BINARY_LITERAL_DEFLATED:
1498                 free(desc->buffer);
1499                 desc->buffer = data;
1500                 dst_size = patch->deflate_origlen;
1501                 break;
1502         }
1503         if (!desc->buffer)
1504                 return -1;
1505         desc->size = desc->alloc = dst_size;
1506         return 0;
1507 }
1508
1509 static int apply_binary(struct buffer_desc *desc, struct patch *patch)
1510 {
1511         const char *name = patch->old_name ? patch->old_name : patch->new_name;
1512         unsigned char sha1[20];
1513         unsigned char hdr[50];
1514         int hdrlen;
1515
1516         if (!allow_binary_replacement)
1517                 return error("cannot apply binary patch to '%s' "
1518                              "without --allow-binary-replacement",
1519                              name);
1520
1521         /* For safety, we require patch index line to contain
1522          * full 40-byte textual SHA1 for old and new, at least for now.
1523          */
1524         if (strlen(patch->old_sha1_prefix) != 40 ||
1525             strlen(patch->new_sha1_prefix) != 40 ||
1526             get_sha1_hex(patch->old_sha1_prefix, sha1) ||
1527             get_sha1_hex(patch->new_sha1_prefix, sha1))
1528                 return error("cannot apply binary patch to '%s' "
1529                              "without full index line", name);
1530
1531         if (patch->old_name) {
1532                 /* See if the old one matches what the patch
1533                  * applies to.
1534                  */
1535                 write_sha1_file_prepare(desc->buffer, desc->size,
1536                                         blob_type, sha1, hdr, &hdrlen);
1537                 if (strcmp(sha1_to_hex(sha1), patch->old_sha1_prefix))
1538                         return error("the patch applies to '%s' (%s), "
1539                                      "which does not match the "
1540                                      "current contents.",
1541                                      name, sha1_to_hex(sha1));
1542         }
1543         else {
1544                 /* Otherwise, the old one must be empty. */
1545                 if (desc->size)
1546                         return error("the patch applies to an empty "
1547                                      "'%s' but it is not empty", name);
1548         }
1549
1550         get_sha1_hex(patch->new_sha1_prefix, sha1);
1551         if (!memcmp(sha1, null_sha1, 20)) {
1552                 free(desc->buffer);
1553                 desc->alloc = desc->size = 0;
1554                 desc->buffer = NULL;
1555                 return 0; /* deletion patch */
1556         }
1557
1558         if (has_sha1_file(sha1)) {
1559                 /* We already have the postimage */
1560                 char type[10];
1561                 unsigned long size;
1562
1563                 free(desc->buffer);
1564                 desc->buffer = read_sha1_file(sha1, type, &size);
1565                 if (!desc->buffer)
1566                         return error("the necessary postimage %s for "
1567                                      "'%s' cannot be read",
1568                                      patch->new_sha1_prefix, name);
1569                 desc->alloc = desc->size = size;
1570         }
1571         else {
1572                 /* We have verified desc matches the preimage;
1573                  * apply the patch data to it, which is stored
1574                  * in the patch->fragments->{patch,size}.
1575                  */
1576                 if (apply_binary_fragment(desc, patch))
1577                         return error("binary patch does not apply to '%s'",
1578                                      name);
1579
1580                 /* verify that the result matches */
1581                 write_sha1_file_prepare(desc->buffer, desc->size, blob_type,
1582                                         sha1, hdr, &hdrlen);
1583                 if (strcmp(sha1_to_hex(sha1), patch->new_sha1_prefix))
1584                         return error("binary patch to '%s' creates incorrect result", name);
1585         }
1586
1587         return 0;
1588 }
1589
1590 static int apply_fragments(struct buffer_desc *desc, struct patch *patch)
1591 {
1592         struct fragment *frag = patch->fragments;
1593         const char *name = patch->old_name ? patch->old_name : patch->new_name;
1594
1595         if (patch->is_binary)
1596                 return apply_binary(desc, patch);
1597
1598         while (frag) {
1599                 if (apply_one_fragment(desc, frag) < 0)
1600                         return error("patch failed: %s:%ld",
1601                                      name, frag->oldpos);
1602                 frag = frag->next;
1603         }
1604         return 0;
1605 }
1606
1607 static int apply_data(struct patch *patch, struct stat *st, struct cache_entry *ce)
1608 {
1609         char *buf;
1610         unsigned long size, alloc;
1611         struct buffer_desc desc;
1612
1613         size = 0;
1614         alloc = 0;
1615         buf = NULL;
1616         if (cached) {
1617                 if (ce) {
1618                         char type[20];
1619                         buf = read_sha1_file(ce->sha1, type, &size);
1620                         if (!buf)
1621                                 return error("read of %s failed",
1622                                              patch->old_name);
1623                         alloc = size;
1624                 }
1625         }
1626         else if (patch->old_name) {
1627                 size = st->st_size;
1628                 alloc = size + 8192;
1629                 buf = xmalloc(alloc);
1630                 if (read_old_data(st, patch->old_name, buf, alloc) != size)
1631                         return error("read of %s failed", patch->old_name);
1632         }
1633
1634         desc.size = size;
1635         desc.alloc = alloc;
1636         desc.buffer = buf;
1637         if (apply_fragments(&desc, patch) < 0)
1638                 return -1;
1639         patch->result = desc.buffer;
1640         patch->resultsize = desc.size;
1641
1642         if (patch->is_delete && patch->resultsize)
1643                 return error("removal patch leaves file contents");
1644
1645         return 0;
1646 }
1647
1648 static int check_patch(struct patch *patch)
1649 {
1650         struct stat st;
1651         const char *old_name = patch->old_name;
1652         const char *new_name = patch->new_name;
1653         const char *name = old_name ? old_name : new_name;
1654         struct cache_entry *ce = NULL;
1655
1656         if (old_name) {
1657                 int changed = 0;
1658                 int stat_ret = 0;
1659                 unsigned st_mode = 0;
1660
1661                 if (!cached)
1662                         stat_ret = lstat(old_name, &st);
1663                 if (check_index) {
1664                         int pos = cache_name_pos(old_name, strlen(old_name));
1665                         if (pos < 0)
1666                                 return error("%s: does not exist in index",
1667                                              old_name);
1668                         ce = active_cache[pos];
1669                         if (stat_ret < 0) {
1670                                 struct checkout costate;
1671                                 if (errno != ENOENT)
1672                                         return error("%s: %s", old_name,
1673                                                      strerror(errno));
1674                                 /* checkout */
1675                                 costate.base_dir = "";
1676                                 costate.base_dir_len = 0;
1677                                 costate.force = 0;
1678                                 costate.quiet = 0;
1679                                 costate.not_new = 0;
1680                                 costate.refresh_cache = 1;
1681                                 if (checkout_entry(ce,
1682                                                    &costate,
1683                                                    NULL) ||
1684                                     lstat(old_name, &st))
1685                                         return -1;
1686                         }
1687                         if (!cached)
1688                                 changed = ce_match_stat(ce, &st, 1);
1689                         if (changed)
1690                                 return error("%s: does not match index",
1691                                              old_name);
1692                         if (cached)
1693                                 st_mode = ntohl(ce->ce_mode);
1694                 }
1695                 else if (stat_ret < 0)
1696                         return error("%s: %s", old_name, strerror(errno));
1697
1698                 if (!cached)
1699                         st_mode = ntohl(create_ce_mode(st.st_mode));
1700
1701                 if (patch->is_new < 0)
1702                         patch->is_new = 0;
1703                 if (!patch->old_mode)
1704                         patch->old_mode = st_mode;
1705                 if ((st_mode ^ patch->old_mode) & S_IFMT)
1706                         return error("%s: wrong type", old_name);
1707                 if (st_mode != patch->old_mode)
1708                         fprintf(stderr, "warning: %s has type %o, expected %o\n",
1709                                 old_name, st_mode, patch->old_mode);
1710         }
1711
1712         if (new_name && (patch->is_new | patch->is_rename | patch->is_copy)) {
1713                 if (check_index && cache_name_pos(new_name, strlen(new_name)) >= 0)
1714                         return error("%s: already exists in index", new_name);
1715                 if (!cached) {
1716                         if (!lstat(new_name, &st))
1717                                 return error("%s: already exists in working directory", new_name);
1718                         if (errno != ENOENT)
1719                                 return error("%s: %s", new_name, strerror(errno));
1720                 }
1721                 if (!patch->new_mode) {
1722                         if (patch->is_new)
1723                                 patch->new_mode = S_IFREG | 0644;
1724                         else
1725                                 patch->new_mode = patch->old_mode;
1726                 }
1727         }
1728
1729         if (new_name && old_name) {
1730                 int same = !strcmp(old_name, new_name);
1731                 if (!patch->new_mode)
1732                         patch->new_mode = patch->old_mode;
1733                 if ((patch->old_mode ^ patch->new_mode) & S_IFMT)
1734                         return error("new mode (%o) of %s does not match old mode (%o)%s%s",
1735                                 patch->new_mode, new_name, patch->old_mode,
1736                                 same ? "" : " of ", same ? "" : old_name);
1737         }
1738
1739         if (apply_data(patch, &st, ce) < 0)
1740                 return error("%s: patch does not apply", name);
1741         return 0;
1742 }
1743
1744 static int check_patch_list(struct patch *patch)
1745 {
1746         int error = 0;
1747
1748         for (;patch ; patch = patch->next)
1749                 error |= check_patch(patch);
1750         return error;
1751 }
1752
1753 static inline int is_null_sha1(const unsigned char *sha1)
1754 {
1755         return !memcmp(sha1, null_sha1, 20);
1756 }
1757
1758 static void show_index_list(struct patch *list)
1759 {
1760         struct patch *patch;
1761
1762         /* Once we start supporting the reverse patch, it may be
1763          * worth showing the new sha1 prefix, but until then...
1764          */
1765         for (patch = list; patch; patch = patch->next) {
1766                 const unsigned char *sha1_ptr;
1767                 unsigned char sha1[20];
1768                 const char *name;
1769
1770                 name = patch->old_name ? patch->old_name : patch->new_name;
1771                 if (patch->is_new)
1772                         sha1_ptr = null_sha1;
1773                 else if (get_sha1(patch->old_sha1_prefix, sha1))
1774                         die("sha1 information is lacking or useless (%s).",
1775                             name);
1776                 else
1777                         sha1_ptr = sha1;
1778
1779                 printf("%06o %s ",patch->old_mode, sha1_to_hex(sha1_ptr));
1780                 if (line_termination && quote_c_style(name, NULL, NULL, 0))
1781                         quote_c_style(name, NULL, stdout, 0);
1782                 else
1783                         fputs(name, stdout);
1784                 putchar(line_termination);
1785         }
1786 }
1787
1788 static void stat_patch_list(struct patch *patch)
1789 {
1790         int files, adds, dels;
1791
1792         for (files = adds = dels = 0 ; patch ; patch = patch->next) {
1793                 files++;
1794                 adds += patch->lines_added;
1795                 dels += patch->lines_deleted;
1796                 show_stats(patch);
1797         }
1798
1799         printf(" %d files changed, %d insertions(+), %d deletions(-)\n", files, adds, dels);
1800 }
1801
1802 static void numstat_patch_list(struct patch *patch)
1803 {
1804         for ( ; patch; patch = patch->next) {
1805                 const char *name;
1806                 name = patch->new_name ? patch->new_name : patch->old_name;
1807                 printf("%d\t%d\t", patch->lines_added, patch->lines_deleted);
1808                 if (line_termination && quote_c_style(name, NULL, NULL, 0))
1809                         quote_c_style(name, NULL, stdout, 0);
1810                 else
1811                         fputs(name, stdout);
1812                 putchar('\n');
1813         }
1814 }
1815
1816 static void show_file_mode_name(const char *newdelete, unsigned int mode, const char *name)
1817 {
1818         if (mode)
1819                 printf(" %s mode %06o %s\n", newdelete, mode, name);
1820         else
1821                 printf(" %s %s\n", newdelete, name);
1822 }
1823
1824 static void show_mode_change(struct patch *p, int show_name)
1825 {
1826         if (p->old_mode && p->new_mode && p->old_mode != p->new_mode) {
1827                 if (show_name)
1828                         printf(" mode change %06o => %06o %s\n",
1829                                p->old_mode, p->new_mode, p->new_name);
1830                 else
1831                         printf(" mode change %06o => %06o\n",
1832                                p->old_mode, p->new_mode);
1833         }
1834 }
1835
1836 static void show_rename_copy(struct patch *p)
1837 {
1838         const char *renamecopy = p->is_rename ? "rename" : "copy";
1839         const char *old, *new;
1840
1841         /* Find common prefix */
1842         old = p->old_name;
1843         new = p->new_name;
1844         while (1) {
1845                 const char *slash_old, *slash_new;
1846                 slash_old = strchr(old, '/');
1847                 slash_new = strchr(new, '/');
1848                 if (!slash_old ||
1849                     !slash_new ||
1850                     slash_old - old != slash_new - new ||
1851                     memcmp(old, new, slash_new - new))
1852                         break;
1853                 old = slash_old + 1;
1854                 new = slash_new + 1;
1855         }
1856         /* p->old_name thru old is the common prefix, and old and new
1857          * through the end of names are renames
1858          */
1859         if (old != p->old_name)
1860                 printf(" %s %.*s{%s => %s} (%d%%)\n", renamecopy,
1861                        (int)(old - p->old_name), p->old_name,
1862                        old, new, p->score);
1863         else
1864                 printf(" %s %s => %s (%d%%)\n", renamecopy,
1865                        p->old_name, p->new_name, p->score);
1866         show_mode_change(p, 0);
1867 }
1868
1869 static void summary_patch_list(struct patch *patch)
1870 {
1871         struct patch *p;
1872
1873         for (p = patch; p; p = p->next) {
1874                 if (p->is_new)
1875                         show_file_mode_name("create", p->new_mode, p->new_name);
1876                 else if (p->is_delete)
1877                         show_file_mode_name("delete", p->old_mode, p->old_name);
1878                 else {
1879                         if (p->is_rename || p->is_copy)
1880                                 show_rename_copy(p);
1881                         else {
1882                                 if (p->score) {
1883                                         printf(" rewrite %s (%d%%)\n",
1884                                                p->new_name, p->score);
1885                                         show_mode_change(p, 0);
1886                                 }
1887                                 else
1888                                         show_mode_change(p, 1);
1889                         }
1890                 }
1891         }
1892 }
1893
1894 static void patch_stats(struct patch *patch)
1895 {
1896         int lines = patch->lines_added + patch->lines_deleted;
1897
1898         if (lines > max_change)
1899                 max_change = lines;
1900         if (patch->old_name) {
1901                 int len = quote_c_style(patch->old_name, NULL, NULL, 0);
1902                 if (!len)
1903                         len = strlen(patch->old_name);
1904                 if (len > max_len)
1905                         max_len = len;
1906         }
1907         if (patch->new_name) {
1908                 int len = quote_c_style(patch->new_name, NULL, NULL, 0);
1909                 if (!len)
1910                         len = strlen(patch->new_name);
1911                 if (len > max_len)
1912                         max_len = len;
1913         }
1914 }
1915
1916 static void remove_file(struct patch *patch)
1917 {
1918         if (write_index) {
1919                 if (remove_file_from_cache(patch->old_name) < 0)
1920                         die("unable to remove %s from index", patch->old_name);
1921         }
1922         if (!cached)
1923                 unlink(patch->old_name);
1924 }
1925
1926 static void add_index_file(const char *path, unsigned mode, void *buf, unsigned long size)
1927 {
1928         struct stat st;
1929         struct cache_entry *ce;
1930         int namelen = strlen(path);
1931         unsigned ce_size = cache_entry_size(namelen);
1932
1933         if (!write_index)
1934                 return;
1935
1936         ce = xcalloc(1, ce_size);
1937         memcpy(ce->name, path, namelen);
1938         ce->ce_mode = create_ce_mode(mode);
1939         ce->ce_flags = htons(namelen);
1940         if (!cached) {
1941                 if (lstat(path, &st) < 0)
1942                         die("unable to stat newly created file %s", path);
1943                 fill_stat_cache_info(ce, &st);
1944         }
1945         if (write_sha1_file(buf, size, blob_type, ce->sha1) < 0)
1946                 die("unable to create backing store for newly created file %s", path);
1947         if (add_cache_entry(ce, ADD_CACHE_OK_TO_ADD) < 0)
1948                 die("unable to add cache entry for %s", path);
1949 }
1950
1951 static int try_create_file(const char *path, unsigned int mode, const char *buf, unsigned long size)
1952 {
1953         int fd;
1954
1955         if (S_ISLNK(mode))
1956                 return symlink(buf, path);
1957         fd = open(path, O_CREAT | O_EXCL | O_WRONLY, (mode & 0100) ? 0777 : 0666);
1958         if (fd < 0)
1959                 return -1;
1960         while (size) {
1961                 int written = xwrite(fd, buf, size);
1962                 if (written < 0)
1963                         die("writing file %s: %s", path, strerror(errno));
1964                 if (!written)
1965                         die("out of space writing file %s", path);
1966                 buf += written;
1967                 size -= written;
1968         }
1969         if (close(fd) < 0)
1970                 die("closing file %s: %s", path, strerror(errno));
1971         return 0;
1972 }
1973
1974 /*
1975  * We optimistically assume that the directories exist,
1976  * which is true 99% of the time anyway. If they don't,
1977  * we create them and try again.
1978  */
1979 static void create_one_file(char *path, unsigned mode, const char *buf, unsigned long size)
1980 {
1981         if (cached)
1982                 return;
1983         if (!try_create_file(path, mode, buf, size))
1984                 return;
1985
1986         if (errno == ENOENT) {
1987                 if (safe_create_leading_directories(path))
1988                         return;
1989                 if (!try_create_file(path, mode, buf, size))
1990                         return;
1991         }
1992
1993         if (errno == EEXIST) {
1994                 unsigned int nr = getpid();
1995
1996                 for (;;) {
1997                         const char *newpath;
1998                         newpath = mkpath("%s~%u", path, nr);
1999                         if (!try_create_file(newpath, mode, buf, size)) {
2000                                 if (!rename(newpath, path))
2001                                         return;
2002                                 unlink(newpath);
2003                                 break;
2004                         }
2005                         if (errno != EEXIST)
2006                                 break;
2007                         ++nr;
2008                 }
2009         }
2010         die("unable to write file %s mode %o", path, mode);
2011 }
2012
2013 static void create_file(struct patch *patch)
2014 {
2015         char *path = patch->new_name;
2016         unsigned mode = patch->new_mode;
2017         unsigned long size = patch->resultsize;
2018         char *buf = patch->result;
2019
2020         if (!mode)
2021                 mode = S_IFREG | 0644;
2022         create_one_file(path, mode, buf, size);
2023         add_index_file(path, mode, buf, size);
2024 }
2025
2026 static void write_out_one_result(struct patch *patch)
2027 {
2028         if (patch->is_delete > 0) {
2029                 remove_file(patch);
2030                 return;
2031         }
2032         if (patch->is_new > 0 || patch->is_copy) {
2033                 create_file(patch);
2034                 return;
2035         }
2036         /*
2037          * Rename or modification boils down to the same
2038          * thing: remove the old, write the new
2039          */
2040         remove_file(patch);
2041         create_file(patch);
2042 }
2043
2044 static void write_out_results(struct patch *list, int skipped_patch)
2045 {
2046         if (!list && !skipped_patch)
2047                 die("No changes");
2048
2049         while (list) {
2050                 write_out_one_result(list);
2051                 list = list->next;
2052         }
2053 }
2054
2055 static struct cache_file cache_file;
2056
2057 static struct excludes {
2058         struct excludes *next;
2059         const char *path;
2060 } *excludes;
2061
2062 static int use_patch(struct patch *p)
2063 {
2064         const char *pathname = p->new_name ? p->new_name : p->old_name;
2065         struct excludes *x = excludes;
2066         while (x) {
2067                 if (fnmatch(x->path, pathname, 0) == 0)
2068                         return 0;
2069                 x = x->next;
2070         }
2071         if (0 < prefix_length) {
2072                 int pathlen = strlen(pathname);
2073                 if (pathlen <= prefix_length ||
2074                     memcmp(prefix, pathname, prefix_length))
2075                         return 0;
2076         }
2077         return 1;
2078 }
2079
2080 static int apply_patch(int fd, const char *filename)
2081 {
2082         unsigned long offset, size;
2083         char *buffer = read_patch_file(fd, &size);
2084         struct patch *list = NULL, **listp = &list;
2085         int skipped_patch = 0;
2086
2087         patch_input_file = filename;
2088         if (!buffer)
2089                 return -1;
2090         offset = 0;
2091         while (size > 0) {
2092                 struct patch *patch;
2093                 int nr;
2094
2095                 patch = xcalloc(1, sizeof(*patch));
2096                 nr = parse_chunk(buffer + offset, size, patch);
2097                 if (nr < 0)
2098                         break;
2099                 if (use_patch(patch)) {
2100                         patch_stats(patch);
2101                         *listp = patch;
2102                         listp = &patch->next;
2103                 } else {
2104                         /* perhaps free it a bit better? */
2105                         free(patch);
2106                         skipped_patch++;
2107                 }
2108                 offset += nr;
2109                 size -= nr;
2110         }
2111
2112         if (whitespace_error && (new_whitespace == error_on_whitespace))
2113                 apply = 0;
2114
2115         write_index = check_index && apply;
2116         if (write_index && newfd < 0)
2117                 newfd = hold_index_file_for_update(&cache_file, get_index_file());
2118         if (check_index) {
2119                 if (read_cache() < 0)
2120                         die("unable to read index file");
2121         }
2122
2123         if ((check || apply) && check_patch_list(list) < 0)
2124                 exit(1);
2125
2126         if (apply)
2127                 write_out_results(list, skipped_patch);
2128
2129         if (show_index_info)
2130                 show_index_list(list);
2131
2132         if (diffstat)
2133                 stat_patch_list(list);
2134
2135         if (numstat)
2136                 numstat_patch_list(list);
2137
2138         if (summary)
2139                 summary_patch_list(list);
2140
2141         free(buffer);
2142         return 0;
2143 }
2144
2145 static int git_apply_config(const char *var, const char *value)
2146 {
2147         if (!strcmp(var, "apply.whitespace")) {
2148                 apply_default_whitespace = strdup(value);
2149                 return 0;
2150         }
2151         return git_default_config(var, value);
2152 }
2153
2154
2155 int cmd_apply(int argc, const char **argv, char **envp)
2156 {
2157         int i;
2158         int read_stdin = 1;
2159         const char *whitespace_option = NULL;
2160
2161         for (i = 1; i < argc; i++) {
2162                 const char *arg = argv[i];
2163                 char *end;
2164                 int fd;
2165
2166                 if (!strcmp(arg, "-")) {
2167                         apply_patch(0, "<stdin>");
2168                         read_stdin = 0;
2169                         continue;
2170                 }
2171                 if (!strncmp(arg, "--exclude=", 10)) {
2172                         struct excludes *x = xmalloc(sizeof(*x));
2173                         x->path = arg + 10;
2174                         x->next = excludes;
2175                         excludes = x;
2176                         continue;
2177                 }
2178                 if (!strncmp(arg, "-p", 2)) {
2179                         p_value = atoi(arg + 2);
2180                         continue;
2181                 }
2182                 if (!strcmp(arg, "--no-add")) {
2183                         no_add = 1;
2184                         continue;
2185                 }
2186                 if (!strcmp(arg, "--stat")) {
2187                         apply = 0;
2188                         diffstat = 1;
2189                         continue;
2190                 }
2191                 if (!strcmp(arg, "--allow-binary-replacement") ||
2192                     !strcmp(arg, "--binary")) {
2193                         allow_binary_replacement = 1;
2194                         continue;
2195                 }
2196                 if (!strcmp(arg, "--numstat")) {
2197                         apply = 0;
2198                         numstat = 1;
2199                         continue;
2200                 }
2201                 if (!strcmp(arg, "--summary")) {
2202                         apply = 0;
2203                         summary = 1;
2204                         continue;
2205                 }
2206                 if (!strcmp(arg, "--check")) {
2207                         apply = 0;
2208                         check = 1;
2209                         continue;
2210                 }
2211                 if (!strcmp(arg, "--index")) {
2212                         check_index = 1;
2213                         continue;
2214                 }
2215                 if (!strcmp(arg, "--cached")) {
2216                         check_index = 1;
2217                         cached = 1;
2218                         continue;
2219                 }
2220                 if (!strcmp(arg, "--apply")) {
2221                         apply = 1;
2222                         continue;
2223                 }
2224                 if (!strcmp(arg, "--index-info")) {
2225                         apply = 0;
2226                         show_index_info = 1;
2227                         continue;
2228                 }
2229                 if (!strcmp(arg, "-z")) {
2230                         line_termination = 0;
2231                         continue;
2232                 }
2233                 if (!strncmp(arg, "-C", 2)) {
2234                         p_context = strtoul(arg + 2, &end, 0);
2235                         if (*end != '\0')
2236                                 die("unrecognized context count '%s'", arg + 2);
2237                         continue;
2238                 }
2239                 if (!strncmp(arg, "--whitespace=", 13)) {
2240                         whitespace_option = arg + 13;
2241                         parse_whitespace_option(arg + 13);
2242                         continue;
2243                 }
2244
2245                 if (check_index && prefix_length < 0) {
2246                         prefix = setup_git_directory();
2247                         prefix_length = prefix ? strlen(prefix) : 0;
2248                         git_config(git_apply_config);
2249                         if (!whitespace_option && apply_default_whitespace)
2250                                 parse_whitespace_option(apply_default_whitespace);
2251                 }
2252                 if (0 < prefix_length)
2253                         arg = prefix_filename(prefix, prefix_length, arg);
2254
2255                 fd = open(arg, O_RDONLY);
2256                 if (fd < 0)
2257                         usage(apply_usage);
2258                 read_stdin = 0;
2259                 set_default_whitespace_mode(whitespace_option);
2260                 apply_patch(fd, arg);
2261                 close(fd);
2262         }
2263         set_default_whitespace_mode(whitespace_option);
2264         if (read_stdin)
2265                 apply_patch(0, "<stdin>");
2266         if (whitespace_error) {
2267                 if (squelch_whitespace_errors &&
2268                     squelch_whitespace_errors < whitespace_error) {
2269                         int squelched =
2270                                 whitespace_error - squelch_whitespace_errors;
2271                         fprintf(stderr, "warning: squelched %d whitespace error%s\n",
2272                                 squelched,
2273                                 squelched == 1 ? "" : "s");
2274                 }
2275                 if (new_whitespace == error_on_whitespace)
2276                         die("%d line%s add%s trailing whitespaces.",
2277                             whitespace_error,
2278                             whitespace_error == 1 ? "" : "s",
2279                             whitespace_error == 1 ? "s" : "");
2280                 if (applied_after_stripping)
2281                         fprintf(stderr, "warning: %d line%s applied after"
2282                                 " stripping trailing whitespaces.\n",
2283                                 applied_after_stripping,
2284                                 applied_after_stripping == 1 ? "" : "s");
2285                 else if (whitespace_error)
2286                         fprintf(stderr, "warning: %d line%s add%s trailing"
2287                                 " whitespaces.\n",
2288                                 whitespace_error,
2289                                 whitespace_error == 1 ? "" : "s",
2290                                 whitespace_error == 1 ? "s" : "");
2291         }
2292
2293         if (write_index) {
2294                 if (write_cache(newfd, active_cache, active_nr) ||
2295                     commit_index_file(&cache_file))
2296                         die("Unable to write new cachefile");
2297         }
2298
2299         return 0;
2300 }